ch13 expression

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ch13 expression
2012-11-01 21:14:17
chapter 13 expression microbiology

chapter 13 notes from presceott
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  1. areas where regulation of gene expression occurs
    • transcription inititiation
    • transcription elongation
    • translation
    • posttranslation
  2. constitutive genes
    housekeeping genes that are expressed continuously
  3. inducible genes
    genes that code for inducible enzymes such as beta galactosidase
  4. beta galactosidase
    an inducible enzyme that functions in a catabolic pathway
  5. where do inductin and repression occur in transcription initiation
    the activity of regulatory proteins
  6. regulatory proteins
    inhibit transcription (negative control) or promote transcription (positive control)
  7. regulatory protein activity is modified by what
    effector proteins
  8. effector proteins affect what phase of replication
  9. negative control
    prescence of repressor at regulatory site which decreases mRNA synthesis
  10. operons
    sequence of bases coding for one or more polypeptides nad promoter and operator or activator binding sites
  11. lac operon negative control
    regulated by lac represor which binds to the operator
  12. lac operon positive controlq
    regulated by catabolite activator protein (CAP) which binds to CAP site
  13. positive control
    presence of an activator protein at a regulatory region that promotes transcription
  14. catabolite activator protein
    coordinates regulation of catabolite operons
  15. 2 forms of CAP
    • acive form is bound to cAMP
    • inactive form is free of cAMP
  16. cAMP levels controlled by
    adenyl cyclase
  17. when is adenyl cyclase active
    when little or no glucose is present
  18. T/F
    CAP works in absence of glucose
  19. diauxic growth
    biphasic growth patter from preferred use of one carbon source over another when both are available
  20. T/F
    catabolite repression plays a role in diauxic growth
  21. tryptophan operon
    negative transcriptional control of repressible genes
  22. when does tryptophan operon function
    in the absence of tryptophan
  23. what other processes regulate tryptophan
  24. riboswitches
    folding of mRNA leader sequence determines if transcription continues or is terminated
  25. T/F
    ribosweitches involve use of the ribosomes
  26. sRNA's
    non coding rnas that don't function as a normal rna